The risk of the Ebola virus being transmitted during air travel is low because unlike infections such as influenza or tuberculosis, it is not spread by breathing air and airborne particles from an infected person, the World Health Organization said. Nonetheless, all travelers are urged to routinely wash their hands and anyone with an illness consistent with the virus should not be allowed to travel unless it is part of an appropriate medical evacuation.

The agency said that all countries unaffected by the Ebola outbreak in West Africa need to strengthen their ability to detect and immediately contain new cases without doing anything that unnecessarily interferes with international travel or trade. But it said countries don't need to impose travel restrictions and active screening of passengers if they do not share borders with Ebola-affected countries.

A task force to monitor the impact of the Ebola virus on travel and transport has been launched by the U.N. health agency along with the International Civil Aviation Organization, the World Tourism Organization, the Airports Council International, the International Air Transport Association and the World Travel and Tourism Council.

Most of the infections in Liberia, Guinea and Sierra Leone have occurred when family members or friends act as caregivers for those who are ill or during burials that don't follow strict infection prevention and control measures, according to WHO officials.